DNA and vector for repressing expression of gene of lachrymatory factor-producing enzyme, method for repressing expression of gene of lachrymatory factor-producing enzyme with them and vegetables having repressed expression of gene of lachrymatory factor-producing enzyme

Abstract

The object of the present invention is to provide DNA and RNA designed on the basis of the sequence of an enzyme gene for repressing the expression of the enzyme gene generating a lachrymatory factor from a precursor of the lachrymatory factor, and also a vector required for introducing DNA for repressing the expression of the gene of the lachrymatory factor-producing enzyme into a vegetable. The present invention relates to DNA comprising at least one sequence selected from the following sequences and a regulatory sequence connected to said sequence so as to make the transcription possible: (a) a DNA sequence encoding a protein or a polypeptide of a lachrymatory factor-producing enzyme or a part of the DNA sequence in a sense orientation, an antisense orientation or both the orientations, wherein the protein or the polypeptide has an effect of converting 1-propenylsulfenic acid into the lachrymatory factor; (b) a regulatory sequence of a DNA in a vegetable genome determined on the basis of the DNA encoding the protein or the polypeptide of the lachrymatory factor-producing enzyme or a part of the regulatory sequence in a sense orientation, an antisense orientation or both the orientations; and (c) a DNA sequence located between the DNA encoding the protein or the polypeptide of the lachrymatory factor-producing enzyme and the regulatory sequence of the DNA in the vegetable genome DNA determined on the basis of the DNA encoding the protein or the polypeptide of the lachrymatory factor-producing enzyme or a part of the DNA sequence in a sense orientation, an antisense orientation or both the orientations.

Description

TECHNICAL FIELD [0001] The present invention relates to DNA and vector for repressing expression of DNA (gene of lachrymatory factor-producing enzyme) encoding protein or polypeptide having an effect of converting 1-propenylsulfenic acid concerning the formation of lachrymatory factors, generated when plants such as onions are broken into pieces or cut to the lachrymatory factor, a method for repressing expression of gene of lachrymatory factor-producing enzyme with them and vegetables having repressed expression of gene of lachrymatory factor-producing enzyme. [0002] The term “lachrymatory factor” (hereinafter referred to as “LF”) in this specification indicates thiopropanal-S-oxide. The expression “to have the lachrymatory factor-producing enzymatic activity” indicates to have an effect of converting trans-1-propenylsulfenic acid, which is an estimate substrate of the lachrymatory factor-producing enzyme, into a lachrymatory factor or an effect of generating the lachrymatory facto...

AI Technical Summary

Benefits of technology

[0010] Namely, the object of the present invention is to provide DNA and RNA designed on the basis of the sequence of a gene of an enzyme for forming the lachrymatory factor from a precursor of this factor for the purpose of repressing the expression, and also a vector required for introducing the expression-repressing DNA of the gene of the lachrymatory factor-producing enzyme into a vegetable. Another object of the present invention is to provide a method for repressing the expression of the gene of the lachrymatory factor-producing enzyme by using them and also a vegetable in which the expression of the gene of the lachrymatory factor-producing enzyme is repressed. The present invention has great advantages that because the formation of the lachrymatory factor can be essentially repressed, the onion is not influenced by other external factors and also that because no influence is exerted on the amount of the precursor of the lachrymatory factor, the quality of onion is not lowered. Another advantage of the present invention is that the expression of the gene can be repressed in a period shorter than that in ordinary techniques of breeding vegetables which are free from the genetic engineering.

[0011] After intensive investigations made for the purpose of solving the above-described problems, the inventors have succeeded in constructing a means of repressing the expression of a gene of a lachrymatory factor-producing enzyme by using DNA encoding protein or polypeptide of the lachrymatory factor-producing enzyme having an effect of converting 1-propenylsulfenic acid into the lachrymatory factor.

[0012] The present invention also relates to DNA usable for repressing the expression of the gene of the lachrymatory factor-producing enzyme on the basis of the above-described sequence. The DNA constitution is as follows:

[0013] DNA comprising at least one sequence selected from the following sequences and a regulatory sequence connected to said sequence so as to make the transcription possible:

[0014] (a) a gene sequence of a lachrymatory factor-producing enzyme or a part of the gene sequence in a sense orientation, an antisense orientation or both the orientations;

[0015] (b) a regulatory sequence of the DNA in the vegetable genome DNA determined on the basis of the gene sequence of the lachrymatory factor-producing enzyme or a part of the regulatory sequence in a sense orientation, an antisense orientation or both the orientations; and

Problems solved by technology

Therefore, the generation of LF is a serious problem not only in cooking in ordinary kitchens but also in factories for producing dry onion.

However, the onion cultivated in the presence of a reduced amount of PeCSO has a problem that the smell is weakened (p.

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